There's details of this in my build thread
http://www.mk5golfgti.co.uk/forum/index.php/topic,8746.60.htmlThere are a few part numbers listed as follows:
aerial amplifier right: 1K6 035 577 H
aerial amplifier left : 1K6 035 577 R
aerial amplifier right: 1K6 035 577 K (for models with diversity)
aerial amplifier left : 1K6 035 577 S (for models with diversity)
aerial amplifier right: 1K6 035 577 T (for models with nav)
aerial amplifier left: 1K6 035 577 AA (for models with nav)
You'll have to figure out which is appropriate for your car